Maggie Brown: With TV’s many platforms, how do you measure success?

Measuring success in theatre is pretty easy thanks to a box office tally of tickets, reaction from the audience and critics, and trends in booking. For television it is different. Now the British Audience Research Board measurement system has formally introduced Dovetail after years of testing. It added three streams: viewing on laptops, tablets and smartphones.

This was a careful response to changes in viewing habits needed to augment the traditional method of ‘overnights’ – the returns from meters installed to measure TV set-top viewing. In the past decade, broadcasters have carried out experiments to see how best to serve flighty younger viewers, with short dramas, comedy turns such as Trigger Happy TV, and news features for small screens. All this while worry mounts that scheduled television is destined to die.

So I was fascinated to see what happened on the television drama event of the year – BBC1’s Bodyguard, which ended on September 23 with a huge audience of 14.3 million, including 3.9 million who watched afterwards via catch up. This was the biggest rating for a drama episode since the current database was introduced in 2006.

The three non-TV streams added a relatively modest one million extra viewers: 397,000 for laptop viewing, 306,000 for tablets and 161,000 for iPhones. So the vast majority wanted to soak up the drama of Richard Madden extracting himself from a suicide-bomb vest on the big screen. That is where it was the most enjoyable given the choice. And on Sunday evenings, when this played out, most viewers are on their sofas. So it’s hardly surprising that the successfully recast Doctor Who was also able to help BBC1 to a stellar evening.

The other factor in the success of these two shows is the grafting and skill of their creators and showrunners. Jed Mercurio’s long career started when he burst on the scene in a cynically shocking and memorably funny series about junior doctors called Cardiac Arrest. It ran between 1994 and 1996.

Since then, Mercurio has experienced successes and disappointments. Bodies on BBC2, the drama that ollowed Cardiac Arrest, offered a bleak view of a disintegrating NHS. It starred Max Beesley and was cancelled after two series despite winning awards. Then came Line of Duty in 2013 and the breakout second series, which starred Keeley Hawes and provided BBC2 with its highest-rating drama that year. I was amazed it didn’t transfer to BBC1, until, belatedly, its fourth series.

As the showrunner, as well as writer, Mercurio picks his cast. Chris Chibnall, the showrunner of Doctor Who, has also grafted to get where he is and is respected in the industry. He took over from Steven Moffat after cutting his teeth on Doctor Who spin-off Torchwood and then Broadchurch. Work with them if you can. Or if you can’t, sit and enjoy their work on your sofa in front of the television – rather than your phone – just like many millions of others.

Maggie Brown contributes to the Guardian, Observer and the Media Podcast and is the author of The Story of Channel 4